1. Field of the Invention
The present invention relates to a MEMS microphone package structure. More particularly, the present invention relates to a MEMS microphone package structure which has a smaller package size and increased structural strength.
2. Description of the Prior Art
As shown in FIG. 1, the conventional micro-chip-microphone 10 includes a base 11, a back chip 12, a diaphragm chip 13 and a field effect transistor 14. The back chip 12 is disposed on and electrically connected to the base 11. The back chip 12 has a back electrode 12a and a plurality of through-holes 12b. The diaphragm chip 13 has an electrode layer 13a, a diaphragm 13b and a separator 13c. The diaphragm chip 13 is attached to the back chip 12 by means of separator 13c and electrically connected to the field effect transistor 14. The field effect transistor 14 is disposed on and electrically connected to the base 11. When sound energy applies on the electrode layer 13a of the diaphragm chip 13, the diaphragm 13b deforms and affects the electric capacity of the electrode layer 13a, the diaphragm 13b and back electrode 12a so that the field effect transistor 14 may transfer the changed electric capacity as electric signals. As shown in FIG. 1, the back electrode 12a of the back chip 12, the diaphragm 13b of the diaphragm chip 13 and the field effect transistor 14 must be electrically connected if the electric signals need transferring. The back electrode 12a, the diaphragm 13b, electrode layer 13a and the field effect transistor 14 have to be electrically connected through the base 11, which causes uncertainty of fabrication and the size of the base 11 larger than the combination of the back chip 12, the diaphragm chip 13 and the field effect transistor 14 to protect the back chip 12, the diaphragm chip 13 and the field effect transistor 14. Those all make the size of the micro-chip-microphone 10 not able to be further reduced.